kenwood ddx6029 no mo’ nav modules?

Hey everybody new to the forums. I've got a customer I installed a Kenwood DDX 6029 for in an 06' Corvette [LS2, Punisher paint scheme; if you're in Houston this weekend check it out at the Corvette Expo at the GRB convention center its pretty sweet], anyways he pulled it out his old Corvette a few weeks back. Its hooked up to a PAC OS2-BOSE, he's also has XM hooked up, and a Kenwood BU camera which are both working fine, I'm having problems with the Navigation. Being that its an older model he has an external nav unit, a KNA-G520 to be exact, which is no longer available. After finishing the the install I tested all components, as I said everything worked except for his navigation, I went into the set-up menu and enabled navigation, but when I select it from the source menu all I get is a blue screen, less the side menu [source, settings, etc...] and the source label at the top which says navigation, no map, no loading or searching status, nothing. I tried resetting the head unit, I check all the connections on the Nav module everything is good. So I'm assuming the module is bad. That being said if anyone knows of something else I should check/test please enlighten me. If the module is bad is there anything I can do to get him navigation without buying a whole new screen? From what I've read the current nav modules will not work with his older screen, and I don't have time to wait on one to be shipped, like I said he's got a show to be at Friday. Is there anything I can do other than recommend he buy a new screen? Thanks for the help - &E

did you try switching the vedio input sorce (button)?

yah, I tried that the night I was working on it. He just needs to buy a new screen unfortunately. Thanks for the advice though.